Hi, I am a novice knitter too, but because no one answered yet, I'll give it a shot. To simplify things, lets pick the size that you are working to be the first size appearing in the brackets, then the pattern becomes:
K3, m1, (K7,m1) repeat 3 times
if we pick the second size, then the patten is
K2, m1, (K5, m1) repeat 5 times
The repeat only applies to the stitches in parentheses, so in the last case the (K5, m1) is repeated 5 times.
I think this is correct. If not, I apologise in advance.